406,491. Ball joints; fastenings; electric couplings. TAMPIER, R. J. C., 1, Rue de Bellevue, Boulogne-sur-Seine, France. March 17, 1933, Nos. 8166, 8167, and 8168. Convention dates, March 19, 1932, Aug. 10, 1932, and Nov. 17, 1932. [Classes 44 and 65 (ii).] A ball joint, for control rods, for attaching control wires to levers or electric cables to sparking plugs, or for mounting engines and other parts in aircraft and motor vehicles, is provided with means for taking up all play while in use, comprising a block sliding in the main casing and pressed against the ball by a spring which can be compressed by a cam member adapted to move transversely of the casing or to rotate about an axis transverse to the casing, the cam being moved to relieve the pressure of the spring to allow easy separation of the joint elements when desired. In Fig. 5, the socket member 25 has a sliding bearing block 26 which engages the ball under pressure of a spring 27 bearing against another sliding block 28 ; the block 28 is held in the position shown, in which the spring is fully compressed and the ball member 24 cannot be withdrawn, by an eccentric cam element 29 (which may be cylindrical in section) on a member 29<1> rotatable in the socket member. The member 29 is held in the position shown by a lever passing through it and engaging a notch in the member 25, as shown at 25<1> in Fig. 2, in which the parts 22, 23, 23<1> correspond to the parts 28, 29, 29<1> in Fig. 5. Rotation of the member 29<1> moves the cam element 29 away from block 28, thus reducing the compression of the spring and allowing the bearing block 26 to be pushed back and the ball member to be withdrawn. In Fig. 5 a cap 35 fixed to the end of a control wire 32 carries a pin 33 engaging bayonet slots 34 in the socket member 25 against the pressure of a spring 31. In the modification shown in Fig. 2, for a control rod transmitting torsional force, the ball 15 is contained in a second ball member 13 which works in the housing 14; the member 13 is slotted at one side to receive a web of the bearing block 19, which slides in the socket member of the joint against a spring 21 in a similar manner to the member 26 in Fig. 5. The end of the bearing web of the member 19 is shaped to fit the ball 15, and its sides engage the sides of the slot in member 13 to transmit torsional force, the member 19 also having projections (not shown) engaging grooves in the socket member for the same purpose. To facilitate assembly of the locking mechanism, the member 23<1> may have a portion of the body part at 23<x> cut away, forming a flat, so that when inserting the member 23<1> into place the flat at 23<x> passes the member 22 without necessitating the full compression of the spring 21. In a modification, Fig. 7, the rear end of the block 60, corresponding to 28 of Fig. 5, is partly inclined, and the member 29<1> of Fig. 5 is replaced by a member 58 slidable axially across the socket member 61 and having a tapered part to engage the block 60. The parts are shown in the position in which the compression of the spring is relieved ; in the locking position, the member 58 is held by a ridge 581 engaging a groove 60<1> in the block 60. In a modification of this construction, the member 58 is screw-threaded, engaging a threaded hole in the socket 61. The axis of the ball stem may be in line with that of the socket member, and in this case the part of the socket member forming the bearing for the ball is made as a cap detachable from the main portion, being attached thereto by a bayonet joint, which may use the member 29<1> as a pin to engage bayonet slots in the detachable cap, or by a wire attached to the ends of the member 29<1> and bent to engage behind a flange on the cap. In a further modification, the member 29<1> is prevented from rotation when in the locking position by a wire clip pivoted in one end of it and adapted to embrace the socket member. Fig. 6 shows a connection for an electric cable 53 to a sparking plug 36. The ball joint is similar to that shown in Fig. 5, but the rotating member 44 has a second cam element 46 on the opposite side to the one (45) for the ball joint, and this. cam element 46 engages a sliding member 48 which acts through a spring 49 to press a contact member 50 against the end of the wire 52 of the cable 53. The end of the cable is provided with pins 54 which co-operate with bayonet slots in the socket member of the joint. The locking lever 44<1> of the member 44 is insulated. The double cam arrangement of Fig. 6 may be applied to double ball-joints, the cable attachment being replaced by a ball joint similar to that at the other end. Fig. 15 shows a double ball joint applied as a fastening for a tank 88 in an aircraft. In this construction the bearing blocks 100, 101 are positively withdrawn, when the spring pressure is released, by a cord 99 passing through a bore in the rotating locking member 96 ; the locking member is rotated from any convenient point by a cord 98 fixed to a pulley 97 on the member 96. The cranked member 96 may be replaced by a threaded taper member. In a modification of the single joint, Fig. 20, the rotating or longitudinally moving locking member is replaced by a cam lever 120, pivoted in the socket member of the joint and having two spring arms 123 which embrace the socket member when turned to the locking position, to prevent accidental unlocking.